Initially manufactured as atest article not intended for spaceflight, it was used for ground testing of the Space Shuttle orbiter's structural design. However, after NASA found that their original plan to upgradeEnterprise for spaceflight would be more expensive than upgradingChallenger, the orbiter was pressed into operational service in theSpace Shuttle program. Lessons learned from the first orbital flights ofColumbia led toChallenger's design possessing fewerthermal protection system tiles and a lighter fuselage and wings. This led to it being 2,200 pounds (1,000 kilograms) lighter thanColumbia, though still 5,700 pounds (2,600 kilograms) heavier thanDiscovery.
Challenger was named afterHMSChallenger, a Britishcorvette that was the command ship for theChallenger Expedition, a pioneering global marine research expedition undertaken from 1872 through 1876.[2] TheApollo 17Lunar Module, which landed on the Moon in 1972, was also namedChallenger.[2]
Challenger being prepared in 1985 for its penultimate flight,STS-61-AChallenger atop aCrawler-transporter, en route to the launch site for its final flight,STS-51-L
Because of the low production volume of orbiters, the Space Shuttle program decided to build a vehicle as aStructural Test Article, STA-099, that could later be converted to a flight vehicle. The contract for STA-099 was awarded to North American Rockwell on July 26, 1972, and construction was completed in February 1978.[3] After STA-099's rollout, it was sent to aLockheed test site in Palmdale, where it spent over 11 months in vibration tests designed to simulate entire shuttle flights, from launch to landing.[4] To prevent damage during structural testing, qualification tests were performed to asafety factor of 1.2 times the design limit loads. The qualification tests were used to validate computational models, and compliance with the required 1.4 factor of safety was shown by analysis.[5] STA-099 was essentially a complete airframe of a Space Shuttle orbiter, with only a mockup crew module installed andthermal insulation placed on its forward fuselage.[6]
Challenger being transported byShuttle Carrier Aircraft 905, shortly before being delivered in 1982
NASA planned to refit the prototype orbiterEnterprise (OV-101), used for flight testing, as the second operational orbiter; butEnterprise lacked most of the systems needed for flight, including a functional propulsion system, thermal insulation, a life support system, and most of the cockpit instrumentation. Modifying it for spaceflight was considered to be too difficult, expensive, and time-consuming. Since STA-099 was not as far along in the construction of its airframe, it would be easier to upgrade to a flight article. Because STA-099's qualification testing prevented damage, NASA found that rebuilding STA-099 into a flightworthy orbiter would be less expensive than refittingEnterprise. Work on converting STA-099 to operational status began in January 1979, starting with the crew module (the pressurized portion of the vehicle), as the rest of the vehicle was still being used for testing by Lockheed. STA-099 returned to the Rockwell plant in November 1979, and the original, unfinished crew module was replaced with the newly constructed model. Major parts of STA-099, including the payload bay doors, body flap, wings, and vertical stabilizer, also had to be returned to their individual subcontractors for rework. By early 1981, most of these components had returned to Palmdale to be reinstalled. Work continued on the conversion until July 1982, when the new orbiter was rolled out asChallenger.[4]
Challenger, as did the orbiters built after it, had fewer tiles in itsThermal Protection System thanColumbia, though it still made heavier use of the white LRSI tiles on the cabin and main fuselage than did the later orbiters. Most of the tiles on the payload bay doors, upper wing surfaces, and rear fuselage surfaces were replaced withDuPont whiteNomex felt insulation. These modifications and an overall lighter structure allowedChallenger to carry 2,500 lb (1,100 kg) more payload thanColumbia.Challenger's fuselage and wings were stronger and lighter thanColumbia's.[4] The hatch and vertical-stabilizer tile patterns were different from those of the other orbiters.Challenger was the first orbiter to have aheads-up display (HUD) system for use in thedescent phase of a mission, and the first to featurePhase I main engines rated for 104% maximum thrust.
After itsfirst flight in April 1983,Challenger quickly became the workhorse ofNASA'sSpace Shuttle fleet, flying six of nine Space Shuttlemissions in 1983 and 1984. Even when the orbitersDiscovery andAtlantis joined the fleet,Challenger flew three missions a year from 1983 to 1985.Challenger, along withAtlantis, was modified atKennedy Space Center to be able to carry theCentaur-G upper stage in its payload bay. If flightSTS-51-L had been successful,Challenger's next mission would have been the deployment of theUlysses probe with the Centaur to study the polar regions of the Sun.
STS-51-L was the orbiter's tenth and final flight, initially planned to launch on January 26, 1986 (after several technical and paperwork delays). The mission attracted huge media attention, as one of the crew was a civilian schoolteacher,Christa McAuliffe, who was assigned to carry out live lessons from the orbiter (as part of NASA'sTeacher in Space Project). Other members would deploy theTDRS-B satellite and conduct comet observations.
Challenger blasted off at 11:38 am EST on January 28, 1986. Just over a minute into the flight, a faulty booster joint opened up, leading to a flame that melted securing struts which resulted in a catastrophic structural failure and explosion of theExternal Tank. The resulting pressure waves and aerodynamic forces destroyed the orbiter, resulting in the loss of all of the crew.
Challenger was the first Space Shuttle to bedestroyed in a mission disaster.[9] The collected debris of the vessel is currently buried in decommissionedmissile silos atLaunch Complex 31,Cape Canaveral Air Force Station. A section of the fuselage recovered from Space ShuttleChallenger can also be found at the "Forever Remembered" memorial at the Kennedy Space Center Visitor Complex in Florida. Debris from the orbiter sometimes washes up on the Florida coast.[10] This is collected and transported to the silos for storage. Because of its early loss,Challenger was the only Space Shuttle that never wore the NASA"meatball" logo, and was never modified with the MEDS "glass cockpit". The tail was never fitted with a drag chute, which was fitted to the remaining orbiters in 1992.Challenger and sister shipColumbia are the only two shuttles that never visited the Mir Space Station or the International Space Station. In September 2020Netflix releasedChallenger: The Final Flight, a four-part miniseries created by Steven Leckart and Glen Zipper documenting the tragedy firsthand.
In March 1988 the federal government and Morton Thiokol Inc. agreed to pay $7.7 million in cash and annuities to the families of four of the sevenChallenger astronauts as part of a settlement aimed at avoiding lawsuits in the nation's worst space disaster, according to government documents. Morton Thiokol, the company that manufactured the faulty solid rocket booster that caused the accident, paid 60 percent, $4,641,000. The remainder, $3,094,000, was paid by the government.[11]
In September 1988 a federal judge dismissed two lawsuits seeking $3 billion from Space Shuttle rocket-maker Morton Thiokol Inc. byRoger Boisjoly, a former company engineer who warned against the ill-fated 1986Challenger launch.[12]
Guion Bluford becomes first African-American in space. First shuttle night launch and night landing. DeployedINSAT-1B. Carried 261,900 envelopes stamped to commemorate the 25th Anniversary ofNASA, most of which were sold to the public.[13]
First mission to have a private citizen in space (Christa McAuliffe).Broke up after launch, killing all seven astronauts on board. Would have deployedTDRS-B.
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